Human islet transplantation is an experimental method for treating Type 1 Diabetes. The islet cells are isolated from the donor’s pancreas, and once transplanted will hopefully begin to produce insulin in the recipient. This study wanted to test some common immunosupressants–tacrolimus and sirolimus–and their effects on islet cells, which at this point are relatively undefined. They also want to see what these immunosupressants would do when combined with each other and with a glucocorticoid, methylprednisilone. All trials were done in vitro with human cells.
When tacrolimus alone was added to the islet cells, they did not decrease their ability to produce a basal rate of insulin, but did decrease their ability to respond acutely to a high concentration of glucose. Sarolimus had no deleterious effects on the islet cells’ insulin production at all. When the two immunosupressants were combined and added to the cells, they were no more harmful than the tacrolimus alone. When the methylprednisilone was added, there was no decrease in the basal insulin rate, however, the stimulated secretion decreased after an hour in the glucose-dense solution. Methylprednisolone did have another effect: it reduced the pro inflammatory abilities of the immunosupressants. This trial will help pave the way for medication regimens for those receiving islet transplants in the future.
Kloster-Jensen K, Sahraoui A, Vethe NT, et al. Treatment with Tacrolimus and Sirolimus Reveals No Additional Adverse Effects on Human Islets In Vitro Compared to Each Drug Alone but They Are Reduced by Adding Glucocorticoids. J Diabetes Res. 2016;2016:1-9.